Having an actor as gifted and exacting as Michael Kitchen interpret one’s work is undoubtedly a huge boon to writers, but it’s not without its challenges as Anthony Horowitz has described in interviews:

Michael is as responsible as I am for the character of Foyle. Michael Kitchen has always been one of our most revered actors here in Britain. He had never done a long-running television series until Foyle’s War. The only reason he took it on, I think, was because I was able to persuade him that it wouldn’t just be a case of him getting a thud of an envelope through a door every two weeks with a new script; he would be very much part of the creative process. That is what we have done for nearly ten years. It’s not always been easy. Michael is very demanding. One of the funny things about him is that he’s the only actor I know who demands fewer lines. He’ll look at a speech and say to me, “Actually I can do all of that — five lines — with one look.” And the annoying thing is, he’s always right; he can — which means I have to write more dialogue for the other actors to fill out the episode. – PBS Q&A for Series 7

Curiously, he had never taken the lead in a long series. In part, this may have been down to his reputation for being ‘difficult’. …Was he difficult? He was certainly demanding – utterly focused on the character with a rigid determination to ensure that the integrity and the quality of the drama would never be compromised. Sometimes, he would cut or rewrite a scene hours before it was due to be filmed, and I won’t pretend that this wasn’t frustrating. But for him the performance was everything, and the result is there on the screen. I have no doubt at all that a huge part of the success of the show was down to Michael. – Daily Mail (Jan. 5, 2008)